Can muscle fibers be stable on the descending limbs of their sarcomere length-tension relations?
The authors of a paper published in this journal (Allinger et al. (1996) J. Biomechanics 29, 627-633) have concluded, based on a theoretical analysis, that muscle fibers may be stable even if some of their constituent sarcomeres have lengths falling on the descending limbs of their static length-tension relations. This note reconsiders the question of fiber stability and concludes that fibers are unstable if at least one of their sarcomeres is on the descending limb. A positive 'short-range' sarcomere stiffness has no effect on fiber stability, and a positive 'effective stiffness' of the whole fiber does not imply sarcomere stability.
Zahalak
G I
GI
Department of Mechanical Engineering, Washington University, St. Louis, MO 63130, USA.
D000465:Algorithms; D004548:Elasticity; D006801:Humans; D008954:Models, Biological; D009119:Muscle Contraction / Q000502:physiology; D018485:Muscle Fibers, Skeletal / Q000502:physiology* / Q000648:ultrastructure; D012518:Sarcomeres / Q000502:physiology* / Q000648:ultrastructure; D013314:Stress, Mechanical